100040 has 32 divisors (see below), whose sum is σ = 234360. Its totient is φ = 38400.

The previous prime is 100019. The next prime is 100043. The reversal of 100040 is 40001.

100040 = T₂₄ + T₂₅ + ... + T₈₄.

100040 = 20² + 21² + ... + 67².

It can be written as a sum of positive squares in 4 ways, for example, as 24964 + 75076 = 158^2 + 274^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a junction number, because it is equal to n+sod(n) for n = 99997 and 100033.

It is not an unprimeable number, because it can be changed into a prime (100043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1610 + ... + 1670.

2¹⁰⁰⁰⁴⁰ is an apocalyptic number.

100040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 100040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117180).

100040 is an abundant number, since it is smaller than the sum of its proper divisors (134320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

100040 is a wasteful number, since it uses less digits than its factorization.

100040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 100040 is about 316.2910052468. The cubic root of 100040 is about 46.4220762963.

Adding to 100040 its reverse (40001), we get a palindrome (140041).

It can be divided in two parts, 1000 and 40, that multiplied together give a square (40000 = 200²).

The spelling of 100040 in words is "one hundred thousand, forty", and thus it is an iban number.